IPA: /ˌʌn.æn.əˈteɪ.tɪd/
KK: /ʌnˈænəˌteɪtɪd/
Describing something that has not been marked or explained with additional notes or comments.
The research paper included both annotated and unannotated versions of the data.
Unannotated → It is formed from "un-" (meaning not) and "annotate" (from Latin "annotare", meaning to mark or note). The word "unannotated" means not marked or noted, indicating the absence of annotations.
Think of 'not' ('un-') having any 'marks' or 'notes' ('annotate') — that's why unannotated means something that lacks any notes.